ts-node Export `ts-node/esm-register`

Register ts-node/esm loader programmatically using register fn.

See issue #2072

Oct 04 '23 15:10 jlenon7

This is great, we will get rid of

(node:2649) ExperimentalWarning: `--experimental-loader` may be removed in the future; instead use `register()`:
--import 'data:text/javascript,import { register } from "node:module"; import { pathToFileURL } from "node:url"; register("ts-node/esm", pathToFileURL("./")); register("extensionless", pathToFileURL("./"));'

if we use the --import ts-node/esm instead of --loader ts-node/esm for Node 20.x projects

Oct 12 '23 18:10 klippx

Make sure to add esm-register.mjs to the files list in package.json.

Oct 26 '23 17:10 TheUnlocked

Regarding the proposed patch:

The first argument to register(): What is the point of calling pathToFileURL() on it? Why one would want to convert a relative path to a file:// URL?

(I would understand if it were an absolute path, resulting in an absolute URL. And in that case the second argument to register() could be omitted. But why for a relative one? register() is able to resolve relative paths relative to its second argument - that is the purpose of the second argument of register().)
The second argument to register(): What is the meaning of "./" here? It usually means the current working directory of a process. Why not use import.meta.url - the URL of this very module?

(In the ExperimentalWarning, cited by klippx in a comment above, pathToFileURL("./") is used because it is inline code used on the command line. There were no module file, and "./" had a meaning in that case.)

An example can be found here: https://nodejs.org/dist/latest-v20.x/docs/api/module.html#enabling Click "CJS <-> ESM" switch in the top-right corner to show it in ESM syntax.

Nov 15 '23 12:11 kkolinko

Hi @jlenon7 did you have time to look at the proposed changes? Looking forward to this PR to be merged. If I can help, i would love to

Jan 05 '24 14:01 ihmpavel

This looks good and it's nearly identical to the code Node recommends when using legacy --loader, though I'd recommend @thetutlage's suggestion. Is this enough to support --import ts-node/esm or would it have to be exposed?